All fasteners require a means of installation. Tools used for installation of the fasteners are designed to perform different functions to provide a specific force, or series of forces, at a specific area during a specific time of the installation process of the fastener. These tools can be as simple as a hammer used to provide an impact load to the head of a nail, or vastly complex systems employing automated assembly features.
A typical Buckle and Swage type fastener, as illustrated in U.S. Pat. No. 8,434,984, comprises of a pin and sleeve, such that the fastener is supplied as a single unit, and where the sleeve is designed to deform first in a buckling manner to contact and capture the structure, and second in a swage manner where the sleeve is radially squeezed inward to interact with the pin.
FIG. 1A illustrates a typical stump-type Buckle and Swage fastener and FIG. 1B illustrates a typical installation procedure for the fastener of FIG. 1A within a structure. As shown in FIG. 1A, an uninstalled assembled fastener 100 comprises a pin 70 located within a sleeve 50. To install (or secure) the assembled fastener 100 to a work piece, or structure 102, the assembled fastener 100 may be placed in a prepared aperture 104 located within the work piece, or structure 102. Next, a forming anvil 106 may be placed over the end of the sleeve 50 and an installation force F may be applied to both the fastener manufactured head side 120 and fastener upset side 130 of the assembled fastener 100 as shown. As the force F is applied to both sides, the sleeve 50 buckles, deforming radially outward, while collapsing itself such that an upset head 111 is created which is direct contact with the surface 112 of the work piece, or structure 102.
After formation of the upset head 111, continued application of the force F on the forming anvil 106 forces a column section 53 (adjacent to the upset head 111 and extruding from the structure 102) of the sleeve 50 to move radially inward and around externally threaded locking grooves 74 of the pin 70, creating a permanent interlocking feature 110. (See FIG. 1B) The forming anvil 106 is then removed, completing the installation process.
Currently, no installation tool or system is designed to provide external force directly to the sleeve end 130 to create the bulb 111 on the sleeve 50 of the fastener 100. While tools exist to bulb solid rivets, and some existing tools may even have a small recess for alignment, these existing tools are solid and designed to move while in constant contact with the upset end of the rivet. Tools also exist to swage material to pins, but not specifically for integrating pins with sleeves and as such, there is currently no installation tool or installation tool system which combines the two actions of buckle and swage.
Furthermore, it must also be noted that buckling a hollow fastener sleeve to create the desired bulb carries some added intricacies not shared by the buckle process of a solid rivet. Specifically, hollow fastener sleeves are prone to a double buckle or double bulb, a process where a second bulb forms on the sleeve column adjacent to an initial bulb. This can be caused due to the ratio of the height of the column to be buckled as compared to the cross-sectional area of the column being too large, and/or due to the workability of the material used being such that as the first bulb is formed, the material in that area is hardened making the adjacent column section above easier to deform as compared to the continued deformation of the existing bulb. This double bulb scenario is detrimental to the mechanical properties of the fastener as it means the bulb in contact with the structure is significantly smaller than desirable and thus only a fraction of the desired area of the structure at the surface 112 is in contact with the fastener.
In addition to the problems described above, improved fastener installations and mechanical properties are needed for push-type fasteners and pull-type fasteners as well as the buckle and swage fastener 100 shown in FIGS. 1A and 1B. In the case of installing push-type fasteners with a simple flat piece of material, there are several issues that may occur, specifically with flush type fasteners. Referring to FIG. 1B, the fastener manufactured head 120 of any flush type fastener is designed to fit precisely into the matching recess generated within the structure 102. In the case of a push-type flush head fastener, where force is used to hold the fastener manufactured head 120 in place and counter act the installation forces on the fastener upset side 130 during the installation process, it is possible to not properly seat the fastener manufactured head 120 within the structure 102. This can occur if the fastener manufactured head 120 is even slightly smaller than the matching recess. Thus, a large flat stock of material, which spans the gap and is flush to the surface would create a small void between the fastener head and the pocket. It is possible to use a small tool to only make contact with the fastener manufactured head 120, but alignment would be an issue and if the tool is too small the user runs the risk of “dishing” the fastener head such that the defined angle, e.g. 100 degrees, is deformed to an undesirable smaller angle, e.g. 90 degrees, creating voids between the fastener head and the matching recess. In the event of a sleeved fastener, such as the one shown in FIGS. 1A and 1B, too much force applied only on the manufactured head of the pin 70 may cause the sleeve head 55 to deform beyond flush, creating drag on the flying structure if not sanded down, and reducing the desired wall thickness of the fastener head to shank junction, leading to lower mechanical values of tension and fatigue.
In view of the above, what is needed is a tooling installation system having unique tools which provide an external force directly to the sleeve end of a fastener to create a bulb on the sleeve of the fastener. Additionally, the novel tooling installation system described in the present disclosure may define a sleeve capture nose with specific geometry to capture the sleeve column such that a double buckle or double bulb cannot take place.